Frigette a/c unit question.....A/C techs

[Roothawg]

Just wondering if anyone has converted an under dash unit to R134? If so, what did you do about the expansion valve?

I am in A/C class today getting my cert., we have access to a killer Robinair recovery system. Maybe I can borrow??? http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[enjenjo]

Converted several to 134, used the expansion valve as is.they worked fine. Evercool has 134 valves that will fit most underdash units.

[ELpolacko]

Done a few myself, and just to be on the safe side I removed the expansion valve and cleaned out the evap coil with denatured achohol and compressed air. Then I put on a new expansion valve for 134a. Those things are pretty cheap, if you can't find a supplier send your old one to me and I can match it up.

[skipperman]

Valves for 12 and 134 are the same.................it'll work...........

jersey Skip

[38Chevy454]

Technically there is a slight difference in the expansion valves, but practically, the R-12 will work fine with R-134a. It has to do with the low-side pressure on R-134a optimally needs to be slightly lower than R-12. Just be sure to flush the old evap and any parts so you are starting with a clean system without any residual mineral oil. Most conversions use POE ("ester") oil, rather than PAG which is what factory R-134a cars use. Pull a good vacuum and put a new drier in the system. Another word of advice, use as big of a condenser as you can, R-134a is more sensitive to condenser capacity than R-12. Make it a parallel flow condenser design, they are much more efficient than the old tube and fin style common on old R-12 systems.

[Roothawg]

Good deal...I was afraid I might have bought something I couldn't convert.